This invention relates to telescopic rod to rod couplers for use in a spinal implant system to fix a pair of generally parallel spinal rods in a spaced relationship. The telescopic rod sections are assembled together using a 180 degree twisting motion which minimizes the risk of the rod sections accidentally disconnecting during the implant procedure.
In the field of spinal surgery it is common for a surgeon to attach a pair of generally parallel rods to the spinal column to assist in the correction of spinal deformities. A variety of couplers have been disclosed and patented for coupling the spinal rods to the individual vertebra so that tension or compressive forces may be applied to the vertebra for correcting the malady. It may be necessary, during the spinal implant surgery, for the surgeon to couple the spinal rods together using a rod to rod coupler to provide additional stability for the spinal system. A variety of spinal rod to rod couplers are known to achieve the interconnection of the two rods. Generally, such couplers include some type of slide or telescopic device to accommodate the variety of spacings between the rods encountered during surgery. Generally, a locking member of some configuration is provided to securely lock the two telescoping sections together and prevent further telescopic movement.
Heretofore, prior art rod to rod couplers are formed such that prior to the locking member being engaged, the telescoping sections may be easily slid past their extremes and out of engagement with one another. While this is a convenient method of connecting and disconnecting the coupler sections, it can be inconvenient during surgery if the sections accidentally disengage.